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  • Writer's pictureAsset Design & Build

Will my extension need planning permission?

Planning permission can be a thorn in the side of home owners, developers and architects. If you fail to get approval for a project it can increase the timeframe and cost. Fortunately, Asset Design and Build can help. We are one of the most experienced builders Maidenhead and the surrounding area has, so clients get the right service every time.

Our main area of expertise is extensions. They can add a lot of value to a home but you must ensure you get planning permission if it is necessary. The trouble is that not every project will require it. In some cases the work will fall under permitted development, meaning you can do it without the hassle of applying for permission.

When is an extension a permitted development?

If the design of your extension meets certain criteria you will not need planning permission. For example it must not:

Cover more than half of the land around the house.

Extend above the highest point of the roof.

Be over four metres high if it is a single storey extension.

Extend too far beyond the rear wall of a property - three metres for an attached house and four metres for detached.

Be closer than seven metres to the rear boundary if it is a two storey extension.

Have materials that differ from those in the original building.

The best place to look for more info on permitted development rights is the Planning Portal. There is a section for extensions here (link to

Other considerations

The permitted development rights above and on the Planning Portal only apply to houses. The rules are different for flats and maisonettes.

There are also much stricter rules if you live on designated land, including conservation areas, national parks, and Areas of Outstanding Natural Beauty.

If your home is a listed building you also have fewer rights so will require permission for most projects.

Two of the most vital things to think about with any extension are overlooking as well as overshadowing. Your project is more likely to get planning permission if it does not overlook or overshadow a neighbouring property. There are many ways you can design it to avoid both of these or minimise the severity.

Choose a reliable service

Asset Design and Build has a lot of experience with planning permission for extensions. If you need help, call on some of the best builders Maidenhead and the surrounding area can offer. We can guide you, offering tips and also adapting the design if necessary.


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